Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.4.24.3 (collagenase)
18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We isolated a cDNA clone whose expression was lost during immortalization. The subtractive hybridization was performed between a genetically matched pair of mortal and immortal lines of SV40 T antigen-transformed MRC-5. The clone was found to code human interstitial collagenase. The expression of collagenase gene was almost completely shut off in seven out of eight independent immortalized clones. In addition, the levels of collagenase expression were dramatically increased toward crisis in the T antigen-transformed but mortal cells. These findings suggest the possibility that the regulatory mechanism of collagenase expression is related to both processes of in vitro aging and immortalization.
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PMID:Loss of collagenase gene expression in immortalized clones of SV40 T antigen-transformed human diploid fibroblasts. 128 Apr 16

An appropriate balance of matrix synthesis and degradation is required for normal morphogenesis and maintenance of tissue architecture. Extracellular matrix molecules and their receptors, as well as proteinases and their inhibitors, are all involved in matrix remodeling. This report examines the idea that extracellular matrix receptors can regulate matrix remodeling. Rabbit synovial fibroblasts and human embryonic lung fibroblasts (MRC-5) were cultured under two sets of conditions. First, they were plated in serum and allowed to establish an extracellular matrix over a 48 h period. Rat monoclonal antibody to the alpha 5/beta 1 integrin fibronectin receptor or normal rat IgG was added to the medium and the expression of the metalloproteinases was examined. Cells treated with anti-alpha 5/beta 1 expressed procollagenase and prostromelysin, whereas the control cells did not. In both cases the cells were well spread and maintained a well-organized cytoskeleton. In the second condition, cells were plated in serum-free medium on intact fibronectin, anti-alpha 5/beta 1, or fragments of fibronectin that contained the cell-binding domain. Cells attached and spread on all these substrates in a fibronectin receptor-dependent manner. They expressed collagenase and stromelysin on anti-alpha 5/beta 1 and on several fibronectin fragments, but not on intact fibronectin. These data support the hypothesis that the fibronectin receptor can exist in more than one functional state and that these functional states provide information that influences gene expression. Adhesion and spreading are supported by all states, whereas only a subset permits collagenase and stromelysin expression.
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PMID:Signal transduction via the fibronectin receptor: do integrins regulate matrix remodeling? 128 60

Macrophages were identified in the intertubular tissue of the rat testis by loading animals with a particulate vital dye (trypan blue or India ink) and by localizing immunocytochemically a macrophage membrane antigen (MRC W3/25). Leydig cells were identified by the histochemical staining reaction for 3 beta-hydroxysteroid dehydrogenase activity and by a monoclonal antibody. Macrophages were scattered in the interstitial tissue closely attached to and mixed with the Leydig cells. They were never found in the seminiferous tubules. The macrophages comprised about 25% of all the cells in the interstitium. Double staining with a vital dye and a marker antibody showed that all the phagocytosing cells were macrophages and that the Leydig cells did not take up vital dyes. Double staining for the demonstration of the 3 beta-hydroxysteroid dehydrogenase activity and the macrophage antigen likewise revealed two distinctly different cell populations. Crude Leydig cell preparations obtained by collagenase treatment of the testis contained macrophages (12-14%). Macrophages were present throughout the postnatal prepuberal development of the testis. Their density was increased in the cryptorchid and irradiated testis.
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PMID:Macrophages in the interstitial tissue of the rat testis. 241 75

Exposure of quiescent MRC-5 human fibroblasts to growth factors such as epidermal growth factor, basic fibroblast growth factor or embryonal carcinoma-derived growth factor resulted in the induction of mRNA transcripts encoding the metalloproteinases collagenase and stromelysin and the specific metalloproteinase inhibitor TIMP, whilst expression of collagen and fibronectin was relatively unaffected. Exposure of quiescent cells to growth factors in the presence of transforming growth factor beta (TGF-beta) resulted in inhibition of collagenase induction and a synergistic increase in TIMP expression. TGF-beta alone did not significantly induce metalloproteinase or TIMP expression. These effects on mRNA transcripts were reflected in increased secretion of TIMP protein and collagenase activity. Nuclear run-off analysis of growth factor-induced transcription revealed that the TGF-beta modulation of TIMP and collagenase expression was due to transcriptional mechanisms. The observations suggest that TGF-beta exerts a selective effect on extracellular matrix deposition by modulating the action of other growth factors on metalloproteinase and TIMP expression.
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PMID:Transforming growth factor beta modulates the expression of collagenase and metalloproteinase inhibitor. 282 Jul 11

The content and distribution of transferrin receptors (Tf-R) in suspended adult rat hepatocytes were studied using 125I-protein A in combination with either a monoclonal (MRC OX-26) or a polyclonal antibody to Tf-R. Internal receptors were made accessible by permeabilization with digitonin. The number of Tf-R detected depended on the batch of collagenase used for liver perfusion. By using the monoclonal reagent in conjunction with the less damaging of two batches of the enzyme, 129,000 receptors were found per cell, with 47,000 (37%) of these on the surface. The polyclonal reagent yielded Tf-R numbers which were consistently higher than those obtained with MRC OX-26. This difference is interpreted as being due to the binding of several (on the average 5-6) molecules of polyclonal IgG per molecule of Tf-R. Remarkably, transferrin binding by Tf-R was not affected by this cluster of associated IgG and the overlayer of protein A. Parallel studies with 131I-transferrin in a simplified binding assay system yielded surface Tf-R estimates which, in most cases, were close to the values obtained with MRC OX-26. After prolonged exposure to collagenase, the ligand-binding capacity of Tf-R was more affected than its immunoreactivity. In preliminary studies, monensin (10 microM) produced a 32%-50% shift of Tf-R from the surface to the inside, whereas short-term incubation with epidermal growth factor (0.17 mM) brought about no clear-cut Tf-R redistribution.
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PMID:Quantification of rat hepatocyte transferrin receptors with poly- and monoclonal antibodies and protein A. 325 59

The function of the metrial gland of the rat, and particularly of its characteristic population of granulated cells, remains unknown. However, several lines of evidence suggest that the granulated cells may derive from lymphocytes, and play a role in the immunology of pregnancy. In this study, antigen expression by granulated and other cell populations from the metrial glands of rats at Days 13 and 14 of pregnancy was studied by an indirect immunoperoxidase method. Acetone-fixed frozen sections, and cytocentrifuge preparations of collagenase-dispersed metrial gland tissue in which numbers of granulated cells had been increased by density-gradient centrifugation, were used. The primary antibodies used recognised, inter alia, B lymphocytes (MRC OX-3, MRC OX-6, MRC OX-12), T lymphocytes (MRC OX-8, W3/25, MRC OX-19), neutrophils (MRC OX-42) and cells of the monocyte/macrophage series (MRC OX-3, MRC OX-6, MRC OX-42, MRC OX-43). The majority of the granulated cells, including smaller, "immature" forms, were unlabelled by any of these antibodies. Some lymphocytes, and varying numbers of larger, non-granulated cells, were labelled by OX-6, OX-12, W3/25, OX-42 and OX-43. In addition to lymphocytes, labelled cells included neutrophils (OX-42), endothelial cells (OX-43), and probably some macrophages (OX-6, OX-43). OX-12, which recognises the kappa chain of rat IgG, labelled some large cells which may have been stromal cells. These findings do not support the concept that the granulated cells are derived from lymphocytes.
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PMID:Expression of leucocyte antigens by cells from the metrial gland of the pregnant rat. 328 48

Methods have been determined for the isolation, purification and subsequent characterization of separate populations of rat intestinal lymphoid cells, namely intraepithelial (IEL), lamina propria (LPL) and Peyer's patch lymphocytes (PPL). Dissociation of the epithelium from the basement membrane with subsequent release of IEL was achieved by citrate buffer incubation followed by vortex agitation. LPL were released from the remaining tissue by scraping, and PPL were similarly obtained. Some preparations of lamina propria were further subjected to collagenase digestion. After filtration and density gradient centrifugation, average yields of 220 x 10(4) IEL, 54 x 10(4) LPL and 220 x 10(4) PPL per gram of gut were obtained. Immunofluorescence characterization demonstrated that cells bearing the MRC OX8 (T-suppressor) marker predominated in IE1 (73%) and were present in lower concentrations in LPL (26%) and PPL (6%). Cells with the W3/25 (T-helper) marker accounted for a small proportion of each of the lymphocyte preparations. IE1 were unusual in containing a population of cells which were negative for the W3/13 marker for T cells, but were MRC OX8 positive. B lymphocytes were present in PPL (55%) and LPL (31%), but were virtually absent in IEL (less than 1%). Few plasma cells were observed. The techniques described will allow functional investigations to be made and lead to a better understanding of mucosal immunity.
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PMID:Intraepithelial, lamina propria and Peyer's patch lymphocytes of the rat small intestine: isolation and characterization in terms of immunoglobulin markers and receptors for monoclonal antibodies. 704 Feb 14

Fetal livers from inbred rat fetuses at 14 days' gestation were dispersed into a single-cell suspension by physical disruption and collagenase digestion. Pluripotent stem cells were characterized and partially purified by a combination of monoclonal antibodies. These included CD71 (anti-transferrin receptor, MRC-OX26, used for rosetting), Cdw90 (anti-Thy-1, MRC-OX7), and the newly described MRC-OX82 (reacting with myeloiid cells in peritoneal exudate), employed in FACS sorting. Enrichment was monitored by long-term reconstitution of lethally irradiated congenic rats genetically distinguishable from the donor by an allelomorphic variant of the CD45 cell-surface antigen. At intervals from 3 months to 1 year, lymph-node cells and peritoneal exudate cells were biopsied for analysis by two-color flow cytometry--one color to determine donor origin, the other to identify Th cell (CD4+), Tc cell (CD8+), B cell (sIg+ or CD45RC+), neutrophil (OX82+ or OX43-), and macrophage (OX43+) compartments. The degree of chimaerism was taken as the read out of stem-cell activity. No significant differentials between lymph-node and peritoneal exudate chimaerisms were detected in any of the recipients; therefore, the enrichment procedure revealed only pluripotent cells, not stem cells of restricted potency. All recovered stem-cell activity was in the OX26(CD71)-negative, OX7(CDw90)-positive, OX82-positive fraction. In the optimum case, an enrichment of very roughly 200-fold in cell-for-cell activity was obtained. Rat bone-marrow colony-forming units in the spleen (CFUs-12) were found to lack the surface antigens recognized by the monoclonal antibodies CD53 (MRC-OX44), MRC-OX39, MRC-OX59, and 144.2.15. These would provide a strategy for their enrichment by depletion.
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PMID:Enrichment of early fetal-liver hemopoietic stem cells of the rat using monoclonal antibodies against the transferrin receptor, Thy-1, and MRC-OX82. 892 59

Mast cell activation is a characteristic feature of chronic inflammation, a condition that may lead to fibrosis as a result of increased collagen synthesis by fibroblasts. We have investigated the potential of tryptase, the major protease of human mast cells, to stimulate collagen synthesis in the human lung fibroblast cell line MRC-5. Tryptase was isolated from human lung tissue by ion-exchange and affinity chromatography. At concentrations of 18 and 36 mU/ml, tryptase stimulated both an increase in cell numbers, and a fivefold increase in DNA synthesis as determined by methyl-[3H]thymidine incorporation. Similar concentrations of tryptase resulted in a 2.5-fold increase in collagen synthesis as determined both by incorporation of [3H]proline into collagen, and by assay of hydroxyproline concentrations in the supernatants. There was also a twofold increase in collagenolytic activity in the culture medium after tryptase treatment, indicating that the increase in collagen synthesis was not a consequence of decreased collagenase production. All of these actions of tryptase were reduced in the presence of the protease inhibitors leupeptin and benzamidine hydrochloride, indicating a requirement for an active catalytic site. SDS-PAGE and autoradiographic analysis of the [3H]collagen produced by the cells revealed it to be predominantly type I collagen. Our findings suggest that the release of tryptase from activated mast cells may provide a signal for abnormal fibrosis in inflammatory disease.
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PMID:Mast cell tryptase stimulates the synthesis of type I collagen in human lung fibroblasts. 907 41

Expression of telomerase (hTERT) in certain cell types has been shown to extend cellular life span without malignant transformation. We studied the phenotype of 26 telomerase-transduced fibroblast clones (TTFC) generated from a mass culture of hTERT retrovirally transduced MRC-5 cells. About two-thirds of the transduced clones senesced at the expected time or shortly thereafter, despite high levels of expression of telomerase and telomere length maintenance. The remaining one-third of the clones were "immortalized" (followed for over 200 cumulative population doublings). All clones maintained a nontransformed phenotype: contact inhibition, anchorage dependency, lack of tumor formation in nude mice, dose dependency to serum and growth factors, low expression of a matrix metalloproteinase associated with metastatic invasion (MMP-9) and high expression of its inhibitor TIMP-1, and no cytogenetic abnormalities by G-banding. In addition, fibroblast-specific biological parameters, such as colony size, production of collagenase, and response to MMC and gamma radiation were tightly regulated at the clonal and subclonal levels.
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PMID:Clonal variation in phenotype and life span of human embryonic fibroblasts (MRC-5) transduced with the catalytic component of telomerase (hTERT). 1146 Nov 14


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